import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import java.awt.*;

public class Program1 {

    /**
     * @param args
     */
    public static void main(String[] args) {

        JFrame frame = new JFrame("SVN Test");
        Dimension dim = frame.getToolkit().getScreenSize();  
        int screenWidth = dim.width;  
        int screenHeight = dim.height;  
        int frameWidth = screenWidth/3;  
        int frameHeight = screenHeight/3;  
        frame.setSize(frameWidth,frameHeight);  
        frame.setLocation((screenWidth-frameWidth)/2,(screenHeight-frameHeight)/2); 

        JPanel panel = new JPanel();

        JButton button1 = new JButton("Button 1");
        
        JButton button2 = new JButton("Button 2");
        
        JButton button3 = new JButton("Button 3");
        
        JButton button4 = new JButton("Button 4");

        final JLabel label = new JLabel("Hello World");        

        label.setVisible(false);
        
        frame.getContentPane().add(panel);
        panel.add(button1);
        panel.add(button2);
        panel.add(button3);
        panel.add(button4);
        
        panel.add(label);
        frame.setVisible(true);

        button1.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {
            	label.setLocation(150, 90);
                label.setVisible(true);
            }
        });
    }
}